Question

Mendeleev arranged elements known at that time. (4) The vertical columns in the periodic table are called , while the horizontal rows are called . (5) The element eka-boron in Mendeleev’s periodic table is known as in the Modern Periodic table. (6) There was no place for in Mendeleev’s original periodic table. (7) Mendeleev created the group without disturbing the original periodic table. (8) In the Modern Periodic table, the elements are arranged in accordance with their . (9) Two rows shown separately at the bottom of the Modern Periodic table are called and . (10) The contains the group 1 and 2 elements. (11) The d-block elements are called . (12) Elements showing properties of both metals and non-metals are called . (13) Newlands could arrange elements upto out of total 56 elements known. (14) In the family of alkali metals, the number of valence electrons is . (15) There are seven electrons in the outermost shell of the elements, such elements belong to the family of .​

Answer 1

Answer:

Mendeleev arranged all 63 elements; which were discovered till his time; in the order of their increasing relative atomic masses in a tabular form. It is known as Mendeleev's Periodic Table. He divided the table in eight columns and seven rows. The columns are known as groups and rows are known as periods.